curl_easy_duphandle: CURLOPT_COPYPOSTFIELDS read out of bounds

When duplicating a handle, the data to post was duplicated using
strdup() when it could be binary and contain zeroes and it was not even
zero terminated! This caused read out of bounds crashes/segfaults.

Since the lib/strdup.c file no longer is easily shared with the curl
tool with this change, it now uses its own version instead.

Bug: http://curl.haxx.se/docs/adv_20141105.html
CVE: CVE-2014-3707
Reported-By: Symeon Paraschoudis

1 files changed, 47 insertions, 0 deletions

diff --git a/src/tool_strdup.c b/src/tool_strdup.c
new file mode 100644
index 000000000..d661a82f7
--- /dev/null
+++ b/src/tool_strdup.c
@@ -0,0 +1,47 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+#include "strdup.h"
+
+#ifndef HAVE_STRDUP
+char *strdup(const char *str)
+{
+  size_t len;
+  char *newstr;
+
+  if(!str)
+    return (char *)NULL;
+
+  len = strlen(str);
+
+  if(len >= ((size_t)-1) / sizeof(char))
+    return (char *)NULL;
+
+  newstr = malloc((len+1)*sizeof(char));
+  if(!newstr)
+    return (char *)NULL;
+
+  memcpy(newstr,str,(len+1)*sizeof(char));
+
+  return newstr;
+
+}
+#endif